Resin composition, laminated structure, cable, tube, and method for manufacturing the resin composition

Abstract

To provide: a laminate structure with silicone rubber as a base material, the laminate structure having slidability and UV-C resistance throughout even when manufactured continuously for a long time; a cable and a tube with an insulator made of the laminate structure; a resin composition constituting a surface layer of the laminate structure; and a method for manufacturing the same.SOLUTION: In one aspect, a resin composition includes silicone rubber as a base material, silicone resin fine particles 112, metal oxide fine particles, and nanosilica fine particles 114.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a laminated structure, a cable, a tube, and a method for producing the resin composition. [Background technology]

[0002] Conventionally, medical device cables are known that consist of a silicone rubber containing fine particles and have a coating that covers the sheath (see Patent Document 1). Compared to polyvinyl chloride (PVC), which has been commonly used as a sheath material, silicone rubber has advantages such as hardly discoloring over time, but it tends to have poor surface slipperiness.

[0003] The cable sheath described in Patent Document 1 is made of silicone rubber containing fine particles such as silicone resin fine particles, and therefore its surface has irregularities caused by the fine particles. These irregularities reduce the contact area when the sheath comes into contact with other components, thereby improving the slipperiness of the sheath surface, and thus the slipperiness of the cable. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 6723489 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, UV-C light irradiation has attracted attention as a simple, inexpensive, and reliable method for sterilizing medical device cables. However, the resistance of cables to UV-C light (hereinafter referred to as UV-C resistance) is a problem when implementing UV-C light irradiation sterilization. Even cables with silicone rubber sheaths will deteriorate if repeatedly irradiated with UV-C light, and it has been confirmed that cracks will form in the sheath when stress is applied, such as when the cable is bent.

[0006] Therefore, one possible method for providing UV-C resistance in addition to slipperiness to the cable described in Patent Document 1 is to add metal oxide fine particles capable of shielding UV-C light to the coating. However, in this case, in the liquid resin composition which is the raw material for the coating, fine particles for forming irregularities on the surface of the coating, such as silicone resin fine particles, and metal oxide fine particles aggregate and settle, resulting in separation into a layer mainly composed of silicone rubber, which is the base material of the coating, and a layer mainly composed of aggregates.

[0007] This results in an uneven distribution of microparticles for creating surface irregularities and metal microparticles within the resin composition. Consequently, the distribution of these microparticles in the cable coating formed by the resin composition is also uneven, making it difficult to impart slipperiness and UV-C resistance to the entire cable. Furthermore, since the separation of the liquid resin composition progresses over time, when the resin composition is continuously coated onto a cable, the content of microparticles for creating surface irregularities and metal microparticles in the coating varies depending on the location on the cable. In particular, in areas where the coating is formed after a certain amount of time has elapsed, the content of microparticles for creating surface irregularities and metal microparticles may be insufficient, potentially preventing the achievement of the desired slipperiness and UV-C resistance.

[0008] The object of the present invention is to provide a laminated structure made of silicone rubber, which has slipperiness and UV-C resistance throughout even when manufactured continuously for a long period of time, a cable and a tube equipped with an insulator made of the laminated structure, and a resin composition constituting the surface layer of the laminated structure and a method for manufacturing the same. [Means for solving the problem]

[0009] The present invention aims to solve the above problems by providing a resin composition that uses silicone rubber as a base material and includes silicone resin fine particles, metal oxide fine particles, and nanosilica fine particles.

[0010] Furthermore, the present invention aims to solve the above problems by providing a laminated structure comprising a first layer made of silicone rubber as the base material, and a second layer laminated on the first layer, which is made of silicone rubber as the base material and contains silicone resin fine particles, metal oxide fine particles, and nanosilica fine particles.

[0011] Furthermore, the present invention aims to solve the above problems by providing a cable equipped with an insulator made of the above-described laminated structure.

[0012] Furthermore, the present invention aims to solve the above problems by providing a tube equipped with an insulator made of the above-described laminated structure.

[0013] Furthermore, the present invention aims to solve the above problems by providing a method for producing a resin composition, which involves adding nanosilica fine particles to a mixture of silicone rubber, titanium dioxide fine particles, and an organic solvent, and then adding silicone resin fine particles. [Effects of the Invention]

[0014] According to the present invention, there are provided a laminated structure having a silicone rubber as a base material, which has slipperiness and UV-C resistance throughout even when continuously produced for a long time, a cable and a tube provided with an insulator composed of the laminated structure, and a resin composition constituting the surface layer of the laminated structure and a method for producing the same.

Brief Description of Drawings

[0015] [Figure 1] FIG. 1 is a vertical cross-sectional view of a laminated structure according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is a perspective view schematically showing the configuration of an ultrasonic probe cable according to a second embodiment of the present invention. FIG. 2(b) is a cross-sectional view in the radial direction of the cable of the ultrasonic probe cable cut along the cutting line A-A shown in FIG. 2(a). [Figure 3] FIG. 3 is a schematic view showing a configuration example of a coating device used for coating a cable with a coating. [Figure 4] FIGS. 4(a) to 4(c) are cross-sectional views in the radial direction of a medical tube according to a second embodiment of the present invention, respectively. [Figure 5] FIG. 5 is a photographed image of a screw vial containing sample A1 left standing for 120 minutes. [Figure 6] FIG. 6 is a graph showing changes in the width of the separation layer of sample A1 and sample A4 over time after being placed in a static state. [Figure 7] FIG. 7 is a graph showing changes in the width of the separation layer of sample A4 and sample A5 over time after being placed in a static state. [Figure 8] FIG. 8 is a schematic view showing the configuration of a tuning fork vibration type viscometer used for measuring the viscosity of samples A1 to A4. [Figure 9] FIG. 9 is a graph showing the viscosity change rate X with respect to the measurement time of samples A1 to A4. [Figure 10] FIG. 10 is a graph showing the relationship between the viscosity change rate X of samples A1 to A4 and the concentration of nanosilica fine particles in the second layer formed using samples A1 to A4. [Figure 11] Figure 11 is a graph showing the relationship between the viscosity of a liquid resin composition and the concentration of nanosilica particles in the second layer, obtained by viscosity measurements of seven samples with different concentrations of nanosilica particles. [Figure 12] Figure 12 shows optical microscope and scanning electron microscope (SEM) images of the surface of the second layer when using nanosilica nanoparticles with a hydrophilic surface treatment and nanosilica nanoparticles with a hydrophobic surface treatment. [Figure 13] Figure 13 is a graph showing the results of the tensile tests on samples C1 and C2. [Figure 14] Figure 14(a) is a schematic diagram showing the bending test. Figure 14(b) is a cross-sectional view of the wire and the test piece wrapped around the wire, in the radial direction of the wire. [Figure 15] Figure 15 shows observation images of the surface of test pieces cut from samples C1 and C2, observed at 50x magnification using an optical microscope. [Figure 16] Figure 16 shows observation images of the surface of test pieces cut from samples C1 and C2, observed at 500x magnification using a scanning electron microscope. [Modes for carrying out the invention]

[0016] [First Embodiment] (Structure of the laminated structure) Figure 1 is a vertical cross-sectional view of a laminated structure 1 according to a first embodiment of the present invention. The laminated structure 1 comprises a first layer 10 made of silicone rubber as the base material, and a second layer 11 laminated on the first layer 10, which is made of silicone rubber as the base material 111 and contains silicone resin fine particles 112, titanium oxide (TiO2) fine particles 113, and nanosilica fine particles 114.

[0017] The silicone rubber that forms the base material of the first layer 10 and the second layer 11 is a type of silicone resin. Compared to polyvinyl chloride, which is commonly used as a material for cables and tubes used in medical applications, silicone rubber has higher resistance to ultraviolet rays (UV-A, UV-B, and UV-C light).

[0018] The laminated structure 1 can take on various forms depending on its application. For example, when used as an insulator for cables and tubes, it is formed into a tubular shape, and when used as a sheet for applications such as a highly UV-resistant sheet for constant-temperature greenhouses or a UV-shielding sheet (UV-shielding curtain) to block UV leakage from sterilization rooms, it is formed into a sheet shape.

[0019] (Structure of the second layer) The second layer 11 is made of a resin composition that uses silicone rubber as the base material 111 and includes silicone resin fine particles 112, titanium oxide fine particles 113, and nanosilica fine particles 114. As the silicone rubber base material 111 of the second layer 11, for example, an addition reaction type silicone rubber coating agent or a condensation reaction type silicone rubber coating agent can be used. In particular, from the viewpoint of adhesion to the first layer 10, which has silicone rubber as the base material, and abrasion resistance, it is preferable to use an addition reaction type silicone rubber coating agent.

[0020] In order to obtain good slipperiness and predetermined wiping resistance on the surface of the laminated structure 1 by the second layer 11, it is preferable that the thickness of the second layer 11 is 3 μm or more. The second layer 11 may also be laminated on both sides of the first layer 10. There is no particular upper limit to the thickness of the second layer 11, but it is preferable that it be 100 μm or less from the viewpoint of productivity, high flexibility, and high bendability.

[0021] The silicone resin fine particles 112 are included in the second layer 11 to create an uneven surface on the second layer 11. When the surface is uneven, the contact area when the second layer 11 comes into contact with an object is reduced compared to when the surface is flat, and the slipperiness is increased.

[0022] Silicone resin has fewer reactive groups (e.g., methyl groups) and higher hardness than silicone rubber. Therefore, silicone resin microparticles 112 can more effectively suppress deformation of the surface irregularities when the second layer 11 comes into contact with an object than silicone rubber microparticles. This is because, when pressure is applied to the surface of the second layer 11 by the object, the higher the hardness of the microparticles, the more effectively deformation of the surface irregularities of the second layer 11 can be suppressed. This suppresses the increase in the contact area between the second layer 11 and the object, and maintains its slipperiness.

[0023] Furthermore, the interatomic bond energies in the molecular structure of silicone resin are higher than those in the molecular structure of silicone rubber. For this reason, silicone resin has higher resistance to UV-C light than silicone rubber.

[0024] For example, the CH bond, which is abundant in silicone rubber, has a bond energy (approximately 4.27 eV) that is lower than the energy of UV-C light (approximately 6.2 eV), so the bond breaks when irradiated with UV-C light. However, the Si-O bond, which is abundant in silicone resin, has a bond energy (approximately 6.52 eV) that is higher than the energy of UV-C light, so the bond does not break when irradiated with UV-C light. For this reason, silicone resin nanoparticles 112 have superior resistance to UV-C light compared to silicone rubber nanoparticles.

[0025] Furthermore, silicone resin has a lower density than silica. For this reason, silicone resin fine particles 112 are less likely to settle in the liquid silicone rubber that forms the base material during the manufacturing process of the second layer 11 than silica fine particles. In other words, in terms of dispersibility in the liquid silicone rubber (in the second layer 11), silicone resin fine particles 112 are superior to silica fine particles.

[0026] The average particle size of the silicone resin fine particles 112 is, for example, 1 μm or more and 10 μm or less. The concentration (mass%) of the silicone resin fine particles 112 in the second layer 11 is, for example, 10% by mass or more and 60% by mass or less. Here, "average particle size" in this specification refers to the average particle size measured by laser diffraction scattering, including that of titanium oxide fine particles and nanosilica fine particles described later.

[0027] The titanium dioxide nanoparticles 113 contained in the second layer 11 can shield against UV-C light by absorption and / or scattering. Here, UV-C light is ultraviolet light in the wavelength range of 200 to 280 nm. By shielding against UV-C light, the titanium dioxide nanoparticles 113 can suppress the degradation of the silicone rubber matrix material 111 due to UV-C light. The TiO2 constituting the titanium dioxide nanoparticles 113 may be of the anatase type, rutile type, or brookite type, or a mixture of two or more of these. Niobium oxide may also be added to the titanium dioxide to improve its stability. The average particle size of the titanium dioxide nanoparticles 113 is, for example, 100 to 300 nm.

[0028] The Ti concentration in the second layer 11 is preferably 1.0% by mass or more and 4.4% by mass or less. The second layer 11 contains titanium oxide fine particles 113 at a concentration such that the Ti concentration is 1.0% by mass or more, resulting in a total volume of 1404 J / cm³. 2 This method suppresses the occurrence of cracks on the surface of the laminated structure 1 that reach the first layer 10, as demonstrated by a bending test equivalent to 45-50% tensile strength after irradiation with UV-C light. The bending test method and the method for observing the presence or absence of cracks will be described later.

[0029] On the other hand, if the second layer 11 contains titanium dioxide fine particles 113 at a concentration exceeding 4.4% by mass, the surface roughness of the second layer 11 increases. Increased surface roughness makes it easier for dirt and bacteria to adhere and harder to remove. Furthermore, if the second layer 11 contains titanium dioxide fine particles 113 at a concentration exceeding 4.4% by mass, the adhesion between the silicone rubber base material 111 and the silicone resin fine particles 112 decreases, making the silicone resin fine particles 112 more likely to fall off, and reducing the slipperiness of the surface of the second layer 11. For this reason, it is preferable that the Ti concentration in the second layer 11 be 4.4% by mass or less.

[0030] The Ti in the second layer 11 is all contained in the titanium oxide nanoparticles 113. The Ti concentration in the second layer 11 is determined as the average value over a measurement area of ​​125 μm x 95 μm using an energy-dispersive X-ray analyzer (EDS) mounted on a scanning electron microscope (SEM).

[0031] To suppress the formation of aggregates of silicone resin fine particles 112 and titanium dioxide fine particles 113 on the surface of the second layer 11 and to uniformly disperse the titanium dioxide fine particles 113 inside the second layer 11, it is preferable to use titanium dioxide fine particles 113 that have been subjected to a hydrophobic surface treatment. Furthermore, to suppress the formation of aggregates of nanosilica fine particles 114 on the surface of the second layer 11 and to uniformly disperse the titanium dioxide fine particles 113 inside the second layer 11, it is preferable to use nanosilica fine particles 114 that have been subjected to a hydrophobic surface treatment. In other words, by using fine particles that have been subjected to a hydrophobic surface treatment as titanium dioxide fine particles 113 and nanosilica fine particles 114, it is possible to suppress the formation of aggregates of silicone resin fine particles 112 and titanium dioxide fine particles 113, and also suppress the formation of aggregates of nanosilica fine particles 114.

[0032] Furthermore, in order to suppress degradation of the base material 111 by UV-C light, fine particles of other metal oxides such as zinc oxide or iron oxide may be used instead of titanium oxide fine particles 113.

[0033] The nanosilica particles 114 impart thixotropy to the liquid resin composition, which is the raw material for the second layer 11 and serves as a coating solution. At this time, the nanosilica particles 114 form a bulky network structure in the liquid, and this structure slows down the settling rate of the aggregates of silicone resin particles 112 and titanium oxide particles 113, thereby suppressing sedimentation. The average particle size of the nanosilica particles 114 is, for example, 10 to 30 nm.

[0034] In order to effectively suppress the sedimentation of aggregates of silicone resin fine particles 112 and titanium oxide fine particles 113, it is preferable that the mass% concentration of nanosilica fine particles 114 in the second layer 11 is 1.14 times or more the mass% concentration of Ti in the second layer 11. Furthermore, in order to keep the viscosity of the liquid resin composition, which is the raw material for the second layer 11, within a range suitable for forming the second layer 11 with a uniform thickness, it is preferable that the concentration of nanosilica fine particles 114 in the second layer 11 is 11.5% by mass or less.

[0035] (Structure of the first layer) The first layer 10 may also contain titanium dioxide nanoparticles 113, similar to the second layer 11, in order to suppress degradation caused by UV-C light transmitted through the second layer 11.

[0036] Furthermore, as described above, the first layer 10 uses silicone rubber as the base material, but when the first layer 10 is used as a sheath material, silicone rubber to which various crosslinking agents, crosslinking catalysts, anti-aging agents, plasticizers, lubricants, fillers, flame retardants, stabilizers, colorants, and other common compounding agents may be added may be used as the base material.

[0037] (Method of manufacturing a laminated structure) The laminated structure 1 is manufactured by curing a liquid resin composition, which is the raw material for the second layer 11, that is attached to the surface of the first layer 10. The liquid resin composition, which is the raw material for the second layer 11, contains silicone resin fine particles 112, titanium dioxide fine particles 113, nanosilica fine particles 114, silicone rubber, and an organic solvent. The liquid resin composition may also contain fine particles of metal oxides such as zinc oxide and iron oxide instead of titanium dioxide fine particles 113. Furthermore, the liquid resin composition may also contain fine particles of multiple types of metal oxides such as titanium dioxide and zinc oxide.

[0038] In the liquid resin composition, silicone rubber liquefied with an organic solvent contains silicone resin fine particles 112, titanium dioxide fine particles 113, and nanosilica fine particles 114. When the liquid resin composition is heated, the organic solvent vaporizes and the silicone rubber hardens, resulting in a second layer 11 made of the solid resin composition.

[0039] The organic solvent included in the liquid resin composition can be, for example, aromatic hydrocarbon solvents such as toluene and xylene, or aliphatic hydrocarbon solvents such as n-hexane, n-heptane, n-octane, isooctane, nonane, decane, undecane, and dodecane, either alone or in combination of two or more. Alternatively, alcohols such as ethanol and isopropyl alcohol, or acetone can also be used.

[0040] When manufacturing a liquid resin composition, it is preferable to add nanosilica fine particles 114 to a mixture of silicone rubber, titanium dioxide fine particles 113, and an organic solvent, and then add the silicone resin fine particles 112, in order to more effectively suppress the separation of the silicone resin fine particles 112 and titanium dioxide fine particles 113 due to sedimentation of aggregates.

[0041] (Effects of the first embodiment) According to the first embodiment of the present invention, the laminated structure 1 is provided with slipperiness and UV-C resistance by including silicone resin fine particles 112 and titanium oxide fine particles 113 in the second layer 11. Furthermore, in the liquid resin composition which is the raw material for the second layer 11, nanosilica fine particles 114 suppress the settling of aggregates of silicone resin fine particles 112 and titanium oxide fine particles 113. This suppresses the uneven distribution of the silicone resin fine particles 112 and titanium oxide fine particles 113 in the second layer 11 and the decrease in their content, even when the laminated structure 1 is manufactured continuously for a long period of time. In other words, by including nanosilica fine particles 114 in the second layer 11, the above-mentioned slipperiness and UV-C resistance are provided throughout the entire laminated structure 1, even when the laminated structure 1 is manufactured continuously for a long period of time (over a long period of time).

[0042] [Second Embodiment] A second embodiment of the present invention is a cable or tube equipped with an insulator made of a laminated structure 1 according to the first embodiment. Hereinafter, as an example, a cable used in medical ultrasound probe cables will be described.

[0043] Figure 2(a) is a schematic perspective view showing the configuration of an ultrasonic probe cable 2 according to a second embodiment of the present invention. In the ultrasonic probe cable 2, as shown in Figure 2, an ultrasonic probe 32 is attached to one end of the cable 20 via a boot 31 that protects this end. On the other hand, a connector 33 is attached to the other end of the cable 20 to connect to the main body of an ultrasonic imaging device.

[0044] Figure 2(b) is a radial cross-sectional view of the cable 20 of the ultrasonic probe cable 2 cut along the cutting line AA shown in Figure 2(a). Inside the cable 20, for example, multiple wires 21, such as coaxial cables, are housed, and a shield 22, such as a braided shield, is provided to cover these multiple wires 21. A sheath 23 is provided to cover the shield 22. Furthermore, in the cable 20, a coating 24 is formed that covers the periphery of the sheath 23 and is in close contact with the sheath 23.

[0045] The sheath 23 and coating 24 of the cable 20 consist of the first layer 10 and the second layer 11 of the laminated structure 1, respectively. In other words, the laminated structure 1 is used as the sheath 23 and coating 24 in the cable 20. Note that the silicone resin fine particles 112, titanium oxide fine particles 113, and nanosilica fine particles 114 in the coating 24 are not shown in the illustration.

[0046] Since the laminated structure 1, which has slipperiness and UV-C resistance throughout, is used as the insulator (sheath 23 and coating 24) of the cable 20, the cable 20 has slipperiness and UV-C resistance throughout. Therefore, it is possible to suppress snagging caused by stickiness on the surface of the sheath 23 and to perform sterilization by irradiation with UV-C light. The thickness of the coating 24 is, for example, 3 μm to 100 μm.

[0047] (How to manufacture cables) An example of a method for manufacturing the cable 20 according to this embodiment will be described. First, multiple (for example, 100 or more) electric wires 21 are bundled together. Then, a shield 22 is formed to cover the bundled multiple electric wires 21.

[0048] Next, the first layer 10 and the second layer 11 of the laminated structure 1 are formed in order to cover the shield 22, thereby forming the sheath 23 and the coating 24. The sheath 23 is formed, for example, by extrusion molding using an extruder. The coating 24 is formed, for example, using the coating apparatus 4 shown below.

[0049] Figure 3 is a schematic diagram showing an example configuration of a coating device 4 used for coating a cable 20 with a coating 24. The coating device 4 comprises a tank 41, a replenishment introduction tube 42, an electric furnace 43, a pulley 44, and a winding machine 45. Cable 200, which is the cable 20 before it is coated with the coating 24, is continuously supplied to the tank 41 from a supply drum 47. The cable 200 has an electric wire 21, a shield 22, and a sheath 23. A winding drum 46 for winding the cable 20 coated with the coating 24 is set in the winding machine 45.

[0050] The process of forming the coating 24 includes the steps of applying a liquid resin composition 240 as a coating liquid to the surface of the cable 200 and heating the cable 200 to which the liquid resin composition 240 is applied to cure the liquid resin composition 240. The liquid resin composition 240 becomes the coating 24 upon curing. Here, the liquid resin composition 240 is the same as the liquid resin composition that is the raw material for the second layer 11 described in the first embodiment.

[0051] In the step of applying the liquid resin composition 240 to the surface of the cable 200, the cable 200 fed from the supply drum 47 is moved in its longitudinal direction, passing through the liquid resin composition 240 stored in the tank 41, and the liquid resin composition 240 is applied to the surface of the sheath 23.

[0052] Tank 41 has an inlet 41a and an outlet 41b. Cable 200 entering tank 41 from inlet 41a passes through tank 41 laterally toward outlet 41b, with its longitudinal direction being horizontal. A cover 411, such as a gasket or felt, is attached to inlet 41a to cover the cable 200 and prevent leakage. Felt material 412 with holes through which cable 200 can pass is attached to outlet 41b to allow liquid resin composition 240 to adhere to the surface of cable 200. The liquid resin composition 240 that has permeated the porous material of felt material 412 can adhere to the surface of cable 200. Liquid resin composition 240 is replenished into tank 41 as needed from a replenishment introduction tube 42.

[0053] In the process of curing the liquid resin composition 240, the cable 200 to which the liquid resin composition 240 is attached is heated in an electric furnace 43 while being moved in its longitudinal direction, thereby crosslinking the silicone rubber of the liquid resin composition 240. It is preferable to use a catalyst such as platinum to promote this crosslinking. The liquid resin composition 240 dries and hardens upon heating in the electric furnace 43. In the example shown in Figure 3, the electric furnace 43 is positioned laterally to the tank 41, and a pulley 44 is positioned further forward in the cable feeding direction from the electric furnace 43. The cable 200 to which the liquid resin composition 240 is attached moves through the electric furnace 43 so that its longitudinal direction is horizontal.

[0054] The temperature and horizontal length of the electric furnace 43 are set so that the liquid resin composition 240 hardens to a degree that prevents plastic deformation or peeling from occurring in the coating 24 when the cable 20, which has become a coating 24 after hardening, is guided by the pulley 44 and wound onto the winding drum 46.

[0055] After passing through the electric furnace 43, the cable 20 is guided by the pulley 44, changes direction, and is wound onto a winding drum 46 located below the pulley 44. Subsequently, the cable 20 is cut to a predetermined length, the ends are processed, and the ultrasonic probe 32, connector 33, and boot 31 are attached to obtain the ultrasonic probe cable 2.

[0056] Furthermore, as another example of a cable or tube equipped with an insulator made of a laminated structure 1, the configuration of a tube (hollow tube) used for medical applications such as catheters will be described below.

[0057] Figures 4(a) to 4(c) are radial cross-sectional views of medical tubes 70a, 70b, and 70c according to a second embodiment of the present invention, respectively. The medical tube 70a shown in Figure 4(a) has an outer coating 72 on the outer surface 71a of the tube body 71. The medical tube 70b shown in Figure 4(b) has an inner coating 73 on the inner surface 71b of the tube body 71. The medical tube 70c shown in Figure 4(c) has an outer coating 72 and an inner coating 73 on the outer surface 71a and inner surface 71b of the tube body 71, respectively.

[0058] As illustrated by medical tubes 70a, 70b, and 70c, the tube according to this embodiment comprises a tube body 71, an outer coating 72 covering the outer surface 71a of the tube body 71, an inner coating 73 covering the inner surface 71b of the tube body 71, or both the outer coating 72 and the inner coating 73.

[0059] The tube body 71 of the medical tubes 70a, 70b, and 70c consists of the first layer 10 of the laminated structure 1, and the outer coating 72 and inner coating 73 consist of the second layer 11 of the laminated structure 1. Therefore, the medical tubes 70a, 70b, and 70c, like the cable 20 of the ultrasonic probe cable 2 described above, possess overall slipperiness and UV-C resistance. For this reason, when used as a tube into which instruments are inserted, such as a catheter, the instruments can be inserted and removed smoothly, and sterilization by UV-C light irradiation can be performed.

[0060] Furthermore, the tube according to this embodiment can be used in endoscopic surgical instrument tube sets, ultrasonic surgical instrument tube sets, blood analyzer tubes, oxygen concentrator piping, hemodialysis blood circuits, cardiopulmonary bypass circuits, endotracheal tubes, and the like.

[0061] (Effects of the second embodiment) According to a second embodiment of the present invention, by using the laminated structure 1 as an insulator, it is possible to provide cables such as the cable 20 used in ultrasonic probe cables 2, and tubes such as medical tubes 70a, 70b, and 70c, which have slipperiness and UV-C resistance throughout, even when manufactured in long, continuous lengths. [Examples]

[0062] The effect of nanosilica nanoparticles 114 on suppressing the sedimentation of aggregates of silicone resin nanoparticles 112 and titanium dioxide nanoparticles 113 in the liquid resin composition that is the raw material for the second layer 11 was evaluated. Table 1 shows the components and preparation procedures of the five liquid resin compositions (referred to as samples A1 to A5) used in this evaluation.

[0063] [Table 1]

[0064] In Table 1, "Silicone Rubber + TiO2" represents the mass of the mixture of silicone rubber and titanium dioxide nanoparticles 113, "Organic solvent" represents the mass of toluene as the organic solvent, "Nanosilica" represents the mass of nanosilica nanoparticles 114, and "Silicone Resin" represents the mass of silicone resin nanoparticles 112. "Procedure 1" of the "Preparation Procedure" is the procedure of adding nanosilica nanoparticles 114 to the mixture of silicone rubber, titanium dioxide nanoparticles 113, and organic solvent, and then adding silicone resin nanoparticles 112. "Procedure 2" is the procedure of adding silicone resin nanoparticles 112 to the mixture of silicone rubber, titanium dioxide nanoparticles 113, and organic solvent, and then adding nanosilica nanoparticles 114.

[0065] The Ti concentration of the second layer 11 formed using samples A1 to A5 was analyzed using an energy-dispersive X-ray spectrometer (EDS). The average value obtained over a measurement area of ​​125 μm x 95 μm was 1.9 mass% in all cases.

[0066] The nanosilica microparticles 114 used in samples A1 to A5 are all nanosilica microparticles with an average particle size of 0.020 μm, manufactured by Nippon Aerosil Co., Ltd. The silicone resin microparticles 112 used in samples A1 to A5 are all silicone resin microparticles with an average particle size of 2 μm, manufactured by Shin-Etsu Chemical Co., Ltd.

[0067] First, samples A1 and A4 were each stirred 200 times by manual shaking, and then placed into 50 ml screw-cap vials. These were left standing at room temperature (23±2°C), and their appearance was photographed as still images at regular intervals.

[0068] Figure 5 is an image of a screw-cap vial containing sample A1 after standing for 120 minutes. Figure 5 shows the transparent separation layer that appears as aggregates of silicone resin microparticles 112 and titanium dioxide microparticles 113 contained in sample A1 settle. The width of this separation layer increases as the settling of the aggregates of silicone resin microparticles 112 and titanium dioxide microparticles 113 progresses, so the degree of settling can be measured by measuring the width of the separation layer.

[0069] Figure 6 is a graph showing the change in the width of the separation layer of sample A1 and sample A4 over time since being left to stand. The width of the separation layer of sample A1 and sample A4 was measured from the captured images using the image processing software ImageJ.

[0070] As shown in Figure 6, no separation layer appeared in sample Al until 50 minutes had elapsed, but a 2 mm wide separation layer appeared after 120 minutes, and after 160 minutes, the width of the separation layer was 12 mm. In contrast, no separation layer appeared in sample A4 until 130 minutes had elapsed, and a separation layer of less than 0.5 mm appeared between 130 and 160 minutes. Similarly, the width of the separation layers in samples A2 and A3 were measured, but no difference from sample A4 was observed.

[0071] These results suggest that in samples A2 to A4 containing nanosilica nanoparticles 114, the sedimentation of aggregates of silicone resin nanoparticles 112 and titanium dioxide nanoparticles 113 was suppressed by the nanosilica nanoparticles 114.

[0072] Figure 7 is a graph showing the change in the width of the separation layer of samples A4 and A5 over time after being left to stand. Samples A4 and A5 have the same components, as shown in Table 1, but differ in the order in which the silicone resin microparticles 112 and nanosilica microparticles 114 are added. The width of the separation layer of sample A5 was measured using the same method as for samples A1 to A4. Note that the measured value of sample A4 in Figure 7 does not match the measured value of sample A4 in Figure 6, because these measurements were obtained from separate measurements. The measurements of sample A1 and sample A4 in Figure 6 were performed on the same day, and the measurements of sample A4 and sample A5 in Figure 7 were also performed on the same day.

[0073] As shown in Figure 7, sample A4 showed a smaller rate of increase in the width of the separation layer over time than sample A5, and it was found that a difference in the width of the separation layers of the two samples began to appear after 30 to 40 minutes. This is thought to be because adding the nanosilica nanoparticles 114 before the silicone resin nanoparticles 112 causes the titanium dioxide nanoparticles 113 and nanosilica nanoparticles 114 to aggregate, suppressing the formation of aggregates of the settling titanium dioxide nanoparticles 113 and silicone resin nanoparticles 112.

[0074] Next, to investigate the relationship between the degree of sedimentation of aggregates of titanium dioxide nanoparticles 113 and silicone resin nanoparticles 112 and the concentration of nanosilica nanoparticles 114, viscosity measurements were performed on samples A1 to A4.

[0075] Figure 8 is a schematic diagram showing the configuration of the tuning fork vibrating viscometer (SV-10H tuning fork vibrating viscometer manufactured by A&D Co., Ltd.) 5 used to measure the viscosity of samples A1 to A4. The tuning fork vibrating viscometer 5 comprises a container 51 (sample container AX-SV-34) for storing liquid resin compositions 240 such as samples A1 to A4, a vibrator 52 whose tip vibrates with a constant amplitude in the liquid resin composition 240, a temperature sensor 53 for measuring the temperature of the liquid resin composition 240, and an electromagnetic drive unit 54 for vibrating the vibrator 52. The tuning fork vibrating viscometer 5 resonates the vibrator 52 in the liquid resin composition 240 and determines the viscosity from the excitation force required to make the vibrator 52 oscillate with a constant amplitude.

[0076] The mechanism by which viscosity measurement can determine the degree of sedimentation of aggregates of titanium dioxide nanoparticles 113 and silicone resin nanoparticles 112 is as follows: As sedimentation progresses, the solid components of the liquid resin composition 240 accumulate in the lower layer, and it is thought that the viscosity of the lower layer increases. In this state, if the change in viscosity can be measured without applying a force that would agitate the liquid resin composition 240, then that change in viscosity can be said to represent the degree of sedimentation. Since the tuning fork vibration viscometer 5 can measure viscosity with weak vibrations, it can measure the viscosity of the liquid resin composition 240 in real time without applying force. Therefore, the viscosity of the liquid resin composition 240 in a stationary state can be measured using the tuning fork vibration viscometer 5, and the sedimentation state of the liquid resin composition 240 can be quantitatively evaluated.

[0077] Viscosity measurements were performed with the entire measurement system at room temperature (23±2℃). Viscosity measured in real time with the tuning fork vibration viscometer 5 was recorded along with temperature changes using RsVisco data communication software manufactured by A&D Company, Limited.

[0078] Samples A1 to A4 were shaken 200 times by manual shaking immediately before the start of measurement. 10 ml of each sample was then dispensed into container 51, and the measurement was performed while the vibrator 52 of the tuning fork vibratory viscometer 5 remained submerged in the liquid. The measurement results are output as a plot of temperature and viscosity against measurement time.

[0079] The sample temperature was checked to confirm that there were no changes during the measurement time that could affect viscosity. If confirmation was not possible based solely on the temperature value relative to the measurement time, a graph was created with temperature on the x-axis and viscosity on the y-axis to confirm that there was no correlation between viscosity and temperature. If a large temperature change was observed and it was determined that the temperature change was affecting viscosity, the measurement was repeated in a system with a constant temperature.

[0080] Let μ0 be the initial viscosity when the measurement time is 0 minutes, and let μ be the viscosity at measurement time T. T And the rate of change of viscosity from the initial state X is defined as "X = ((μ T The formula "-μ0) / μ0)×100" was used, and the sample viscosity was considered constant when the fluctuation of this rate of change X was within ±2% within a certain period of time. The ±2% index was set considering that the repeatability (standard deviation of measured values) of the tuning fork vibration viscometer 5 is 1% and the influence of external factors affecting the measurement of the tuning fork vibration viscometer 5.

[0081] If, within a certain period of time, the sample temperature remains within a range that does not affect viscosity, and the viscosity change rate X fluctuates within ±2%, then the dispersion state of the particles in the sample is constant. Conversely, if, while the sample temperature remains within a range that does not affect viscosity, the viscosity change rate X fluctuates beyond ±2%, then the dispersion state of the particles in the sample is not constant. In particular, if the viscosity change rate X is increasing, in resin compositions that do not harden over time, such as samples A1 to A4, it can be determined that the particles in the composition are settling.

[0082] Figure 9 is a graph showing the viscosity change rate X as a function of measurement time for samples A1 to A4. According to Figure 9, sample A1, which does not contain nanosilica nanoparticles 114 and showed sedimentation in the separation layer width measurement shown in Figure 6, showed a large increase in viscosity change rate X over time, with the viscosity change rate X being approximately 12% after 120 minutes. From this, it can be concluded that in sample A1, the position of the particles in the sample, mainly aggregates of titanium dioxide nanoparticles 113 and silicone resin nanoparticles 112, was unstable, leading to sedimentation.

[0083] In contrast, samples A2, A3, and A4 showed a smaller increase in viscosity change rate X over time compared to sample A1, with viscosity change rates X after 120 minutes being 8.6%, 4.5%, and 0%, respectively. This indicates that particle sedimentation was suppressed in samples A2, A3, and A4 compared to sample A1.

[0084] However, the viscosity change rate X of samples A2 and A3 increased over time, albeit more slowly than that of sample A1, and was greater than 2% after 120 minutes. This indicates that the viscosity of samples A2 and A3 was not constant and that some particle sedimentation occurred. On the other hand, the viscosity change rate X of sample A4 increased very little over time, remaining within ±2% after 120 minutes. This indicates that the viscosity of sample A4 was almost constant and that almost no particle sedimentation occurred.

[0085] When the second layer 11 is formed using samples A1 to A4, all organic solvents among the components shown in Table 1 are removed. Therefore, the concentrations of nanosilica fine particles 114 in the second layer 11 formed using samples A1, A2, A3, and A4 are 0% by mass, 0.441% by mass, 1.33% by mass, and 2.17% by mass, respectively. Here, the concentration of nanosilica fine particles 114 is calculated as [(mass of nanosilica) / {(mass of silicone rubber)+(mass of TiO2)+(mass of nanosilica)+(mass of silicone resin)}]*100.

[0086] Figure 10 is a graph showing the relationship between the viscosity change rate X of samples A1 to A4 and the concentration of nanosilica fine particles 114 in the second layer 11 formed using samples A1 to A4. In Figure 10, "10 minutes," "30 minutes," "60 minutes," "90 minutes," and "120 minutes" correspond to the measurement times in the graph in Figure 9, respectively.

[0087] As shown in Figure 10, the viscosity change rate X tends to decrease as the concentration of nanosilica particles 114 in the second layer 11 increases. Specifically, when the concentration of nanosilica particles 114 in the second layer 11 is 2.17% by mass or higher, the viscosity change rate X is within ±2% regardless of whether the measurement time is 0 to 120 minutes, indicating that the sedimentation of aggregates of silicone resin particles 112 and titanium dioxide particles 113 is effectively suppressed.

[0088] Here, the concentration of nanosilica nanoparticles 114 necessary to effectively suppress the sedimentation of aggregates of silicone resin nanoparticles 112 and titanium dioxide nanoparticles 113 is proportional to the concentration of titanium dioxide nanoparticles 113. Furthermore, since the Ti contained in the second layer 11 is contained in the titanium dioxide nanoparticles 113, the concentration of nanosilica nanoparticles 114 necessary to effectively suppress the sedimentation of aggregates of silicone resin nanoparticles 112 and titanium dioxide nanoparticles 113 is proportional to the Ti concentration in the second layer 11.

[0089] As described above, the Ti concentration of the second layer 11 formed using samples A1 to A4 is 1.9 mass%, and according to Figure 10, the sedimentation of aggregates of silicone resin particles 112 and titanium oxide particles 113 is effectively suppressed when the concentration of nanosilica particles 114 in the second layer 11 is 2.17 mass% or higher. Therefore, it can be said that the sedimentation of aggregates of silicone resin particles 112 and titanium oxide particles 113 is effectively suppressed when the mass% concentration of nanosilica particles 114 in the second layer 11 is 2.17 / 1.9 times or more, i.e., 1.14 times or more, than the mass% concentration of Ti. Here, the Ti concentration is obtained as the average value in a measurement area of ​​125 μm x 95 μm when the second layer 11 is evaluated using an energy-dispersive X-ray analyzer (EDS) mounted on a scanning electron microscope (SEM).

[0090] On the other hand, in the case of the liquid resin composition that is the raw material for the second layer 11, the higher the viscosity, the more difficult it becomes to form the second layer 11 to a uniform thickness. Also, when coating is performed by the dip coating method, the higher the viscosity, the greater the thickness of the second layer 11. As described above, the thickness of the second layer 11 is preferably 100 μm or less from the viewpoint of high flexibility and high bendability. In this case, the viscosity of the liquid resin composition that is the raw material for the second layer 11 is preferably 30 mPa·s or less.

[0091] Figure 11 is a graph showing the relationship between the viscosity of a liquid resin composition and the concentration of nanosilica particles 114 in the second layer 11, obtained by viscosity measurements of seven samples A1 to A4, which contain different concentrations of nanosilica particles 114. All seven samples used in this viscosity measurement contain the same concentration of titanium oxide particles 113, and the Ti concentration of the second layer 11 formed using these seven samples is 1.9 mass% in all cases. The common conditions for the seven samples are 5.65 g of "silicone rubber + TiO2", 30 g of "organic solvent", and 7 g of "silicone resin". The amount of nanosilica added was varied so that the nanosilica concentration was 0 mass% (sample A1), 0.217 mass%, 0.441 mass% (sample A2), 0.651 mass%, 0.868 mass%, 1.33 mass% (sample A3), and 2.17 mass% (sample A4). The viscosity (mPa·s) of the coating solution at nanosilica concentrations of 0 mass%, 0.217 mass%, 0.441 mass%, 0.651 mass%, 0.868 mass%, 1.33 mass%, and 2.17 mass% was 7.17, 7.17, 7.14, 7.30, 7.49, 7.51, and 8.18, respectively.

[0092] The approximate curve y = 0.1667x shown in Figure 11 2 According to +0.1136x+7.1453, the viscosity of the liquid resin composition becomes 30 mPa·s or less when the concentration of nanosilica fine particles 114 in the second layer 11 is approximately 11.5% by mass or less. For this reason, in order to keep the viscosity of the liquid resin composition within a suitable range, it is preferable that the concentration of nanosilica fine particles 114 in the second layer 11 is 11.5% by mass or less.

[0093] Furthermore, whether nanosilica nanoparticles 114 are treated with a hydrophilic surface or a hydrophobic surface, there is no difference in the effect of suppressing the sedimentation of aggregates of silicone resin nanoparticles 112 and titanium oxide nanoparticles 113. However, when nanosilica nanoparticles treated with a hydrophilic surface are used as nanosilica nanoparticles 114, aggregates of nanosilica nanoparticles 114 may form on the surface of the second layer 11.

[0094] Figure 12 shows optical microscope and scanning electron microscope (SEM) images of the surface of the second layer 11 when hydrophilic surface-treated nanosilica nanoparticles (referred to as hydrophilic nanosilica) and hydrophobic surface-treated nanosilica nanoparticles (referred to as hydrophobic nanosilica) are used as nanosilica nanoparticles 114. In both cases, hydrophobic surface-treated titanium oxide nanoparticles 113 are used as titanium oxide nanoparticles 113. As shown in Figure 12, when hydrophilic surface-treated nanosilica nanoparticles are used as nanosilica nanoparticles 114, fine irregularities are observed on the surface of the second layer 11, which are thought to be due to the presence of aggregates of nanosilica nanoparticles 114.

[0095] Therefore, in order to suppress the formation of aggregates of nanosilica fine particles 114 on the surface of the second layer 11 and to uniformly disperse titanium oxide fine particles 113 inside the second layer 11, it is preferable to use nanosilica fine particles 114 that have been subjected to a hydrophobic surface treatment. [Examples]

[0096] Tests confirmed that the UV-C resistance of the laminated structure 1 did not change when nanosilica particles 114 were added to the second layer 11.

[0097] First, two types of cables 20 (referred to as samples B1 and B2) were prepared, each having a coating 24 formed by dip coating with a liquid resin composition, and the components of the coating 24 differed. Table 2 shows the components of samples B1 and B2. As shown in Table 2, sample B1 contains 2.17 mass% of nanosilica fine particles 114 in the coating 24, while sample B2 does not contain nanosilica fine particles 114 in the coating 24.

[0098] [Table 2]

[0099] Next, the sheath 23 and coating 24 were cut from samples B1 and B2, respectively. The laminate of the sheath 23 and coating 24 cut from sample B1 was designated as sample C1, and the laminate of the sheath 23 and coating 24 cut from sample B2 was designated as sample C2. As described above, the sheath 23 and coating 24 correspond to the first layer 10 and the second layer 11, respectively, so samples C1 and C2 consist of a laminated structure 1.

[0100] Next, using a storage cabinet equipped with a germicidal lamp (DM-5, GL-10 lamp, manufactured by Daishin Kogyo Co., Ltd.), the following conditions were met: internal temperature 25-40°C, internal humidity 28-65%, internal pressure 1 atm (atmospheric pressure), wavelength 253.7 nm, illuminance 1.3 mW / cm². 2 Samples C1 and C2 were irradiated with UV-C light under conditions of irradiation times of 200 hours, 300 hours, 450 hours, and 600 hours. The illuminance meter used was a UVC-254A manufactured by MK Scientific.

[0101] (Tensile test) To verify the UV-C resistance of laminated structure 1 based on its tensile strength, a tensile test was conducted after UV-C light irradiation.

[0102] Sheet-like samples C1 and C2 were punched out using a No. 6 dumbbell to create dumbbell shapes. Then, samples C1 and C2 were irradiated with UV-C light, and a tensile test was performed on them under the conditions of ambient temperature 15-35°C, ambient humidity 28-65RH%, and atmospheric pressure, in accordance with "JIS K6251 (1994)".

[0103] Figure 13 is a graph showing the results of tensile tests on samples C1 and C2. The horizontal axis represents the total irradiation energy of UV-C light (illuminance × irradiation time: J / cm²). 2 The vertical axis shows the elongation at the fracture point. As shown in Figure 13, the elongation at the fracture point of both samples C1 and C2 changes with increasing total irradiation energy of UV-C light, indicating that the elongation at the fracture point changes similarly upon irradiation with UV-C light, regardless of whether or not the second layer 11 contains nanosilica particles 114.

[0104] Specifically, 1404 J / cm² 2The elongation at break measured by the tensile test after irradiation with UV-C light of 1404 J / cm 2 was 210% for Sample C1 containing nanosilica fine particles 114 in the second layer 11 and 195% for Sample C2 not containing nanosilica fine particles 114 in the second layer 11. From this, when irradiated with UV-C light of 1404 J / cm

[0105] It was also found that the value of the elongation at break of the laminated structure 1 containing nanosilica fine particles 114 in the second layer 11 did not decrease by 30% or more with respect to the value of the elongation at break when the second layer 11 did not contain nanosilica fine particles 114. 2 The elongation at break measured by the tensile test after irradiation with UV-C light of 2808 J / cm 2 was 122% for Sample C1 containing nanosilica fine particles 114 in the second layer 11 and 77% for Sample C2 not containing nanosilica fine particles 114 in the second layer 11. From this, when irradiated with UV-C light of 2808 J / cm

[0106] (Flexural test) In order to verify the UV-C resistance of the laminated structure 1 from the strength against bending, a flexural test after UV-C light irradiation was carried out.

[0107] Fig. 14(a) is a schematic diagram showing the state of the flexural test. The test piece 60 in the figure is a rectangular test piece cut from each of Samples C1 and C2. In the flexural test, as shown in Fig. 14(a), the test piece 60 is wound around a conductor (metal wire) 61 with a radius of 0.5 mm, and the overlapping portion of the test piece 60 is sandwiched and fixed from both sides (the illustration of the fixture is omitted). Here, the test piece 60 was cut out from Samples C1 and C2 in a size of 12 mm (circumferential direction of the cable-like Samples B1 and B2) × 18 mm (length direction of the cable-like Samples B1 and B2). Then, the test piece 60 was wound around the conductor 61 such that the 18-mm side was along the circumferential direction of the conductor 61 and the second layer 11 was located on the outside.

[0108] Figure 14(b) is a cross-sectional view of the wire 61 and the test specimen 60 wrapped around the wire 61, in the radial direction of the wire 61. If the radius of the wire 61 is r and the thickness of the test specimen 60 is t, then as shown in Figure 14(b), the longitudinal length of the neutral surface 60a of the test specimen 60 in any angle θ range is (r+t / 2)·θ, and the longitudinal length of the outer surface 60b of the test specimen 60 is (r+t)·θ. Therefore, the longitudinal elongation of the outer surface 60b of the test specimen 60 wrapped around the wire 61 is expressed as {(r+t)·θ-(r+t / 2)·θ} / ((r+t / 2)·θ)×100=t / (2r+t)×100, and since the radius r of the wire 61 is 0.5 mm and the thickness t of the test specimen 60 is 0.82 mm, it is approximately 45%.

[0109] Bending tests were performed on test specimens 60 cut from samples C1 and C2. The surface of test specimen 60 during the bending test (when the second layer 11 was subjected to elongation equivalent to 45-50%) was observed using an optical microscope (Keyence Corporation, Digital Microscope VHX-1000) and a scanning electron microscope (Keyence Corporation, VHX-D510). These observation images are shown in Figures 15 and 16.

[0110] Figure 15 shows an observation image of the surface of test specimens 60 cut from samples C1 and C2, observed at 50x magnification using an optical microscope. Figure 16 shows an observation image of the surface of test specimens 60 cut from samples C1 and C2, observed at 500x magnification using a scanning electron microscope.

[0111] As shown in Figures 15 and 16, the test piece 60 cut from sample C2, which does not contain nanosilica particles 114 in the second layer 11, was irradiated with UV-C light to a total energy of 936 J / cm². 2 , 1404 J / cm 2 , 2106 J / cm 2 , 2808 J / cm 2 In either case, it was confirmed that no cracks occurred on the surface. In this bending test, a crack refers to a recess that extends from the second layer 11 (coating 24) to the first layer 10 (sheath 23).

[0112] Furthermore, a test piece 60 cut from sample C1 containing nanosilica particles 114 in the second layer 11 was subjected to a total UV-C light irradiation energy of 936 J / cm². 2 In this case, no cracks were formed on the surface. The total irradiation energy of UV-C light was 1404 J / cm². 2 , 2106 J / cm 2 , 2808 J / cm 2 In this case, slight cracks occurred, but when ten 1.5 mm × 4.5 mm areas were observed using an optical microscope at a magnification of 50x, cracks were observed in three or fewer of the ten 1.5 mm × 4.5 mm areas. Based on these results, it was determined that the test piece 60 cut from sample C1 containing nanosilica fine particles 114 in the second layer 11 also possessed UV-C resistance.

[0113] In the evaluation of the above embodiment, no significant difference in UV-C resistance was observed between cases where the laminated structure 1 contains nanosilica fine particles 114 in the second layer 11 and cases where it does not. However, as shown in the method for manufacturing the cable 20 above, when forming a coating 24 continuously on a long cable, it is important to suppress the sedimentation of aggregates of silicone resin fine particles 112 and titanium oxide fine particles 113 in the liquid resin composition that is the raw material for the coating 24 in order to maintain the components of the second layer 11. Therefore, the laminated structure 1 containing nanosilica fine particles 114 in the second layer 11 is superior in that it has overall slipperiness and UV-C resistance.

[0114] (Summary of the embodiments) Next, the technical concept understood from the embodiments described above will be described using the reference numerals and other symbols from the embodiments. However, the reference numerals and other symbols in the following description are not limited to the components in the claims that are specifically shown in the embodiments.

[0115] [1] A resin composition comprising silicone rubber as the base material, and containing silicone resin fine particles (112), metal oxide fine particles, and nanosilica fine particles (114).

[0116] [2] The resin composition according to [1] above, wherein the metal oxide fine particles are titanium oxide fine particles (113).

[0117] [3] The resin composition according to [1] above, wherein the metal oxide fine particles are titanium oxide fine particles (113) that have been subjected to a hydrophobic surface treatment.

[0118] [4] A laminated structure (1) comprising a first layer (10) made of silicone rubber as the base material, and a second layer (11) laminated on the first layer (10), which is made of silicone rubber as the base material and contains silicone resin fine particles (112), metal oxide fine particles, and nanosilica fine particles (114).

[0119] [5] The laminated structure (1) according to [4] above, wherein the metal oxide fine particles are titanium oxide fine particles (113), and the mass% concentration of the nanosilica fine particles (114) in the second layer (11) is 1.14 times or more the mass% concentration of Ti, and 11.5% or less by mass.

[0120] [6] The laminated structure (1) according to [5] above, wherein the Ti concentration of the second layer (11) is 1.0 mass% or more and 4.4 mass% or less.

[0121] [7] A cable (20) comprising an insulator (23, 24) made of a laminated structure (1) as described in any one of the above items [4] to [6].

[0122] [8] Tubes (70a, 70b, 70c) comprising insulators (71, 72, 73) made of the laminated structure (1) described in any one of the above items [4] to [6].

[0123] [9] A method for producing a resin composition, comprising adding nanosilica fine particles (114) to a mixture of silicone rubber, titanium dioxide fine particles (113), and an organic solvent, and then adding silicone resin fine particles (112).

[0124] Although embodiments and examples of the present invention have been described above, the present invention is not limited to the above embodiments and examples, and various modifications can be made without departing from the spirit of the invention. Furthermore, the embodiments and examples described above do not limit the invention as defined in the claims. It should also be noted that not all combinations of features described in the embodiments and examples are necessarily essential for solving the problem of the invention. [Explanation of Symbols]

[0125] 1. Laminated structure 10. The first layer 11. Second Layer 111 Base material 112 Silicone resin microparticles 113 Titanium dioxide nanoparticles 114 nano-silica microparticles 2. Ultrasonic probe cable 20 Cables 23 Sheath 24 Coating 70a, 70b, 70c medical tubing 71 Tube body 72 Outer coating 73 Inner coating 240 Liquid resin composition

Claims

1. The material is based on silicone rubber and contains silicone resin microparticles, titanium dioxide microparticles, and nanosilica microparticles. The mass percentage concentration of the silicone resin fine particles is 10% by mass or more and 60% by mass or less. The mass percentage concentration of Ti is between 1.0% by mass and 4.4% by mass. The mass percentage concentration of the nanosilica fine particles is 1.14 times or more the mass percentage concentration of Ti, and 11.5% or less by mass. Resin composition.

2. The titanium oxide nanoparticles are titanium oxide nanoparticles that have undergone a hydrophobic surface treatment. The resin composition according to claim 1.

3. A first layer made of silicone rubber, Laminated on the first layer is a second layer made of silicone rubber as the base material, containing silicone resin fine particles, titanium oxide fine particles, and nanosilica fine particles, Equipped with, In the second layer described above, The mass percentage concentration of the silicone resin fine particles is 10% by mass or more and 60% by mass or less. The mass percentage concentration of Ti is between 1.0% by mass and 4.4% by mass. The mass percentage concentration of the nanosilica fine particles is 1.14 times or more the mass percentage concentration of Ti, and 11.5% or less by mass. Laminated structure.

4. The titanium oxide fine particles are titanium oxide fine particles that have been subjected to a hydrophobic surface treatment. The laminated structure according to claim 3.

5. An insulator comprising a laminated structure according to claim 3 or 4, cable.

6. An insulator comprising a laminated structure according to claim 3 or 4, tube.

7. A method for producing the resin composition according to claim 1 or 2, The resin composition is produced by adding nanosilica fine particles to a mixture of the silicone rubber, titanium oxide fine particles, and organic solvent, then adding silicone resin fine particles to prepare a liquid resin composition, and then heating and curing the liquid resin composition. A method for producing a resin composition.

Images